Three-quarters of writers in liberal democracies are concerned about government surveillance and one-third have censored their own writing because of those fears, according to a new survey.

The analysis from the Pen American Center released on Monday is harshly critical of U.S. spying powers and, its authors said, proves why Congress needs to take action to rein in agencies, such as the FBI or National Security Agency (NSA).

“Fear of government surveillance is prompting many writers living in democratic countries to engage in the kind of self-censorship associated with police states,” Executive Director Suzanne Nossel said in a statement. “We’re all well aware of writers in places like China and Russia who must live life knowing they are always being watched — it’s disturbing to recognize that those in the U.S., Canada, and Australia are now coming to adopt similar behavior.”

The survey covered 772 writers living in 50 countries and found that 75 percent of writers in democratic nations are worried about government snooping. That is nearly on par with the 80 percent concerned about the practice in countries deemed “not free,” such as Russia, China or Sudan.

In the U.S., 27 percent of writers have avoided or considered avoiding writing or speaking about a particular topic because of concerns about spying, according to the report. 

The findings could give support to lawmakers who face an uphill climb to enact tough restrictions on spy agencies such as the NSA.

A legal provision authorizing the agency’s bulk collection of Americans’ phone records is set to expire June 1, setting up a battle. Critics of the spying programs plan to push again to enact tough reforms. A major NSA reform bill was blocked in a procedural vote last month, despite support from the Pen American Center and other organizations.